1. Field of the Invention
The present invention relates to an optical disk apparatus capable of loading a plurality of kinds of optical disks, and a starting method thereof.
2. Description of the Related Art
In addition to conventional optical disks such as CDs and DVDs, BDs (Blu-ray Disks) with more high-density and high-capacity are beginning to come into practical use. For the purpose of loading a plurality of kinds of optical disks, an optical disk apparatus discriminates the kind of optical disk and optimally switches operational conditions of the apparatus in accordance with the discriminated kind of disk.
In order to comply with BD, DVD, and CD disks, the optical disk apparatus includes a three-wavelength optical pickup as an optical system which generates laser light with wavelengths of 405 nm, 660 nm and 780 nm, respectively, and positions the focus of the light beam from an objective lens to a recording surface of each disk. Further, the optical disk apparatus is newly provided with a beam-expander composed of a fixed lens and a movable lens for BD disks in order to correct spherical aberration caused by a disk-plate-thickness error (For example, refer to Japanese Patent Laid-open No. 2005-100481).